WASHINGTON -- Some legislators are going to battle with the Defense Department over Army uniform regulations they say discriminate against African-American women wearing their hair naturally.

The Army issued AR 670-1 changes in a 57-page directive in mid-March addressing male and female grooming standards, fingernails ("males may not wear nail polish"), jewelry, tattoos, and other items for clarification.

The male standards focused on strips of hair left on otherwise shaved heads, sideburn length (no lower than the bottom of the ear opening), and how wide a regulation mustache can be (not up into the nose and not past the corners of the mouth).

The female standards clarify rules for short and medium hair length, and stipulate that the "bulk" of the hair can't extend more than two inches from the scalp. If long hair is tied back in a bun, that can protrude a maximum of three inches from the scalp.

The photos accompanying the guidelines about unauthorized hair include an Afro as an example of hair that's too bulky. Dreadlocks and twists are also shown as non-regulation.

Multiple braids are authorized as long as they're uniform and "tightly interwoven to present a neat, professional, well-groomed appearance." They can be worn loose if they meet the collar-length requirement for medium-length hair or pulled back if longer. Tight, neat cornrows are also allowed, and hair extensions are authorized if they conform to natural hair.

In early April, the women of the Congressional Black Caucus wrote a letter to Defense Secretary Chuck Hagel calling the regulations "discriminatory rules targeting soldiers who are women of color with little regard to what is needed to maintain their natural hair."

"African American women have often been required to meet unreasonable norms as it relates to acceptable standards of grooming in the workplace," stated the letter, led by CBC chairwoman Marcia Fudge (D-Ohio). "Understand that these standards should shift based on each community's unique and practical needs. New cultural norms and trends naturally change, ensuring that no person feels targeted or attacked based on his or her appearance. We believe the Army's updated rules and the way they are written fail to recognize this reality."

"Army officials have responded to criticism of the regulation by saying it applies to all soldiers regardless of race, and that they are meant to protect their safety. However the use of words like 'unkempt' and 'matted' when referring to traditional hairstyles worn by women of color are offensive and biased. The assumption that individuals wearing these hairstyles cannot maintain them in a way that meets the professionalism of Army standards indicates a lack of cultural sensitivity conducive to creating a tolerant environment for minorities."

The caucus women "strongly" encouraged Hagel to "reconsider the updated regulation as it relates to grooming standards and how it allows individuals from every community to feel proud and welcome to serve in our nation's Armed Forces."

On Tuesday, the CBC received a response from Hagel. "I want to assure you that, while none of the Army's revised grooming and appearance policies were designed or intended to discriminate or disparage against any Service Members, I take your concerns very seriously," the secretary wrote.